155 



provided with 2 apical claws. Vibratory plate of mandibular palp less fully 

 developed than in Cytherissa. Legs of right series in male conspicuously 

 transformed, 1st leg distinctly prehensile, 2nd leg with the terminal part very 

 feeble, though apparently 3 articulate. Caudal rami extremely small, in form 

 of 2 thin bisetose lamellae. Genital lobes likewise very small and not produced 

 below. Ripe ova received within the shell-cavity for further development. 



Remarks. This genus, proposed by Jones, has by most recent authors 

 been rejected, and regarded as identical with Cytheridea Bosquet. I think 

 however that the genus ought to be supported, though it is here taken in a 

 sense somewhat different from that formerly adopted by me. It differs from 

 the preceding genus in the general appearance and sculpture of the shell, as 

 also somewhat in the structure of the appendages, and very essentially in the 

 fact, that the ripe ova are received within the shell-cavity for further develop- 

 ment. The peculiar transformation of the legs in the male is a character, 

 which this genus shares with the succeeding one. The type of the present 

 genus is C. torosa Jones, a species closely allied to that described below. 



67. Cyprideis littoralis, Brady. 



PI. LXXI, PI. LXXII, fig. 1. 

 Cytheridea littornlis, Brady, Nat. Hist. Trans. Northumb. and Durham, Vol, III, p. 6. 



Syn: Cytheridea torosa, Brady (not Jones). 

 Cyprideis torosa, G. O. Sars (not Jones). 

 Cytheridea torosa, var. teres, Brady & Norm. 



Specific Characters. Female. Shell, seen laterally, oval reniform in shape, 

 almost equally high behind as in front, greatest height exceeding somewhat 

 half the length, dorsal margin nearly straight in the middle and joining the 

 hind edge by a quite even curve, being more abruptly bent in front, with a 

 slight indication to an angle above the eyes, ventral margin scarcely at all 

 sinuated, anterior extremity well rounded off, posterior obtusely blunted; seen 

 dorsally, oblong ovate in outline, slightly constricted in the middle, with the 

 greatest width far behind and about equalling half the length, anterior extre- 

 mity obtusely pointed, posterior much broader and blunt at the end. Surface 

 of shell evenly convex, without lateral protuberances, but of a dult appearance, 

 being marked with closely set rounded pittings; marginal zone of the valves 

 closely striated: right valve produced at the infero-posteal corner to a short 

 dentiform projection pointing backwards, edges otherwise quite smooth and 

 finely hairy. Anterior antennas with the terminal part about as long as the 

 distal segment of the basal one, middle joint scarcely longer than the 1st. 



